1. Field of the Invention
The invention relates to simultaneous rendering of graphics and video on an image display device, and more particularly includes the detection of video windows, which may be partially hidden by graphics windows.
2. Discussion of Related Art
Multimedia computer systems and televisions typically include a display device, such as a cathode ray tube display (CRT) or liquid crystal display (LCD), plasma display or digital light display upon which information is presented to operators and viewers. The displayed information may be one or a combination of various images, including video, animation, photographs and text. The various images are often displayed in separate windows; and these windows often overlap such that one image is partially or fully covering another window.
FIG. 1A illustrates a computer display presenting graphic-like objects in combination with video-like objects. The Figure shows a computer display 30 including both a video window 2a and a graphics window 3. The video window 2a may contain animation or moving images, for example of a fish swimming in the ocean. The graphics window 3 may contain, for example, computer generated shapes, or text, which may be scrolling. In the illustration shown, the video window 2a partially covers the graphics window 3, resulting in a rectangular video window 2a. 
Typically, data presented on computer display 30 may be characterized as either graphics or video. In general, graphic-like objects are displayed in graphics windows 3, and video-type objects are displayed in video windows 2a. Often these displays appear as a collage of windows.
FIG. 1B illustrates a computer display presenting a second combination of graphic-like objects and video-type objects. The Figure shows a computer display 30 including both a
rectangular video window 2a and a rectangular graphics window 3. Unlike, FIG. 1A, this illustration shows the graphics window 3 partially covering the video window 2a. The uncovered portion of the partially covered video window 2a forms a six-sided polygon 4b, with parallel sides and one concave corner.
FIG. 2A illustrates, in a block diagram, a computer system including a computer, a display processor and a computer display. The computer system includes a computer 10 that communicates to a display processor 20a by way of a first interface 40. The first interface 40 carries an input stream of pixel data. The display processor 20a, in turn, communicates to the computer display 30 by way of a second interface 50a. The second interface 50a carries an output stream of pixel data.
The input and output streams of pixel data are encoded in a manner that can be decoded by the display processor 20a and computer display 30. The display processor 20a receives display pixel data from the computer 10, modifies the pixel data so that an enhanced image may be displayed as well as possibly reformatting the pixel data so that it may be transmitted (e.g. in DVI, HDMI or IEEE 1394 standard formats), and then forwards the modified and possibly reformatted data to the computer display 30 for display thereon.
The streams of pixel data on interfaces 40 and 50a may be digital or analog signals. Each stream of pixel data is segmented into a sequence of frames, with each frame including a plurality of bits. Each frame is segmented into a plurality of lines. Each row is segmented into a plurality of words or bytes. A word represents a picture element (pixel), which provides information on the brightness as well as the color characteristics for that pixel.
Each frame of data may contain one or more windows of information to display. The windows may include a combination of multiple graphics and video windows. As the information to be displayed changes, the data within subsequent frames will change.
The display processor 20a may be a system component, for example, the iScan Pro system or the iScan Plus V2, both manufactured by Silicon Image, Inc. of Sunnyvale, Calif. The display processor 20a may include a semiconductor integrated circuit, for example, the SiI 503, SiI 504 or SiI 861, also both manufactured by Silicon Image. The display processor 20a may be a separate unit (as shown); and can be incorporated in the computer 10, or incorporated in the computer display 30.
Some computer systems allow an operator to configure the display processor 20a to disable, or to enable, the enhancement of images presented on the computer display 30. Digital processing, used to enhance the graphics of prior art display processors 20a, may be unsuitable for video images. Likewise, the digital processing used to enhance video images may be unsuitable for graphics. If the operator disables enhancement, no portion of the computer display 30 is enhanced; and such display attributes as the brightness and contrast might be less than optimum for pleasurable viewing. If the operator enables enhancement, the entire computer display 30 is enhanced. If the operator enables enhancement and enhancement parameters are adapted to graphics, any video images may appear washed out, unnatural and lifeless. If the operator enables enhancement and enhancement parameters are set to those favoring video, the non-video images may appear over-colorized and too bright.
Alternatively, some prior art systems allow for enhancement of only a single rectangular region of the computer display 30. When these prior art systems are faced with overlapping windows resulting in non-rectangular video windows or multiple rectangular regions, only a single rectangular region is enhanced. When presented with the example shown in FIG. 1B, these systems either fail to enhance a portion of the video window 2b or erroneously enhance a portion of the graphics window 3. Similarly, when the prior art systems are faced with multiple video windows, only one video window is enhanced. Additionally, the prior art systems do not allow the operator to customize processing parameters used to enhance video images.
When the display processor 20a is faced with multiple video images, with a partially covered video image, or a completely covered video image, the resulting images in computer display 30 may appear unnatural to the viewer. Therefore, there is a desire to have an apparatus, system and method to better detect the boundaries of multiple video windows and partially covered video windows to allow for customized processing such that the images appear in more natural coloring.